Textbook of Python

Also known as: CPython, Python 3

Python is a high-level, general-purpose programming language created by Guido van Rossum and first released in 1991. Its design philosophy prizes code readability above almost everything else: significant indentation forces a clean visual structure, the syntax reads close to pseudocode, and the standard library follows the principle that there should be "one obvious way to do it." Python is dynamically typed, garbage-collected, and supports multiple programming paradigms including procedural, object-oriented, and functional styles.

The reference implementation is CPython, written in C, which compiles source code to bytecode and executes it on a virtual machine. Alternative implementations include PyPy (JIT-compiled), Jython (JVM), and GraalPy. Python's ecosystem is enormous: the Python Package Index (PyPI) hosts over 500,000 packages spanning web development, data science, machine learning, scientific computing, automation, and education.

Python consistently ranks among the most popular programming languages in the world. Its gentle learning curve makes it a favourite first language, while its depth—decorators, generators, metaclasses, the data model—keeps experts engaged for decades. The language is governed by Python Enhancement Proposals (PEPs) and stewarded by the Python Software Foundation.